The present invention relates to valves, and more particularly a safety choke valve having an improved choke body top.
Adjustable and positive safety choke valves have been widely used in the oil and gas industry for controlling the flow of liquid, such as oil or gas from a well head. These valves are designed to adjustably vary the flow of fluid and allow escape of built up pressure to prevent hazardous build up of high pressure in the flow line.
Typically, such valves comprise a valve body having an L-, T-, or F- shape with multiple orifices to permit passage of fluid or gases through the valve with the means to restrict the flow through the orifices in that valve to vary the flow of such fluid or gases.
The present invention, more particularly concerns itself with provision of an adjustable or positive valve bonnet and head, which is designed to allow manual/hand engagement and disengagement when the pressure is below 50 psi, and provides a safety feature which detects excessive pressure in the valve (before the valve is fully disengaged, thereby averting any possible accidents which may harm the person handling the possible disengagement), and further, allows for pressure bleedoff should the gases or fluids in the valve be under excessive pressure, supplementing conventional pressure escape means available in the currently known valves.
Prior to this design, there were many accidents in the field caused by disengagement of the valve from the stem while the valve contained pressure. The prior designs did not allow for the detection of pressure within the valve, and once the cap was fully disengaged, the valve head would blow off of the stem injuring the operator. The present design allows for the detection of pressure from fluids or gases within the valve before the valve is fully disengaged.